Envelope lock



Dec. 15, 1931*. .1.. w, FITZGERALD 1,83459 ENVELOPE LOCK Filed Jan. 26, 1929 @ya Y I uhn 'fgrald fits i Patented Dec. 15,1931. Y. Y

gUMTED STATES PATENT oFF-Ica JOHN W. FITZGERALD, or Boeren, MASSACHUSETTS.; l

ENvELorE A Loox Application filed January 26, 1929. Serial No. 335,344. .i

This invention relates to improvements in f lationship therewith, the resilient, inwardly Y projecting portions having razor edges adjacent the cooperating element, the space between the resilient, inwardly projecting portions increasing rearwardly, thereby providing more positive and greater holding power between the razor like edges and the cooperating locking element.

Other objects of this invention will appear from the following detailed description of the device, and as disclosed in the single sheet of drawings which is herewith made Va part of this application.

In the drawings velope lock according to'this invention.

Figure 2 represents a perspective view of the envelope lock disclosing the two main portions in detached relationship.

Figure 3 illustrates a planV view of thereceiving member of the envelope lock.

-Figure 4 represents a vertical sectional view of the envelope lock, just previous to bringing the two members of the .fastener i into interlocked relationship.

Figure 5 illustrates a vertical sectional view ofthe envelope lock disclosing the coopi erating fastening element being brought i `into interlocked relationship with the receiv- 3 ing` member.

Figure 6 represents a vertical sectional view of the envelope lock disclosing the two portions thereof in interlocked relationship.

Figure 7 illustrates a plan view of the envelope lock disclosing the two portions thereof in interlocked relationship.

.Flgure 1 illustrates a plan view of the envelope of the ordinary type, and numeral 2- its liap,.adapted to be heldvin'closed relationship to each other by meansfof anv envelope As one modification of this invention, it isV Y preferred that numeral l designate an enlock, comprising areceiving member 3, made from any suitable material, ,and formed by stamping or otherwisefrom a singlejp-iece, thereby greatly freducing the expense of manufacturing, a cooperating iocking elenieptli also formed of a single piece of mate-` ria.;

- Thel receiving. member Sfis formed having outwardly extending'fprongs 5- adapt-edjtoV ellamp'tirmly in positionV on the main body portion 1 of the envelope, while the-fastening -fso element 4 is proyided with prongs `6,'fad`apted to hold-the flapl portion 2 ofthe envelope in -interloc-ked relationship with the fastening element 4. l

rlhe receiving member 3 is provided with a countersunkportio'n comprising a plurality of inwardly extend ing sections 7 ,havingrazor like edges 8 along the inner periphery there-v of. From thisconstruction it is apparent that when the shank portion 9 of the cooperating fastening element 4 extends through the opening l0 in the receiving member 3, the razor like edges 8 will contact with the shank portion 9, owing tothe resiliency of the inwardly extending sections7 and thecap portion 11 of the shank 9 will be located above and overhang the razor like edges 8,'in such a manner that Athe holding power between the two members 3 and 4 will increase as the attempt to separate them'increases.

The countersunkportion of the member 3,

according to this invention, is formedv in such f a manner that the razor `like edges 8 will not tend to be affected materially under strain,

the flexibility of theinwardly extending seci tions 7 depending upon theincreasing space or openings 12 between the sect1ons7, as

clearly disclosed in Figure' 7, wherein the space12 at or4 near the (base of the sections 7l is considerably wider than the space'between thesections atthe razor edges thereof;

A locking fastener for envelopes comprising a receiver made of a Vsingle piece of stampedsheet material and having a flat anvnular outer portion with prongs on its outer periphery and `an inner annular n portion curved first upwardly and inwardly from the inner periphery ofthe outer annular portion, then downwardlyand inwardly, and finally upwardly. and inwardly, forming two Yconcentric, re'versely extending corrugations, the inner portion of the material having ka knife edge, and-said inner portion having narrow radial slots with parallel walls adjacent the knife edge to form extended knife edge bearings surfaces, said slots terminating in enlarged rounded openings extendiiiginto the lower portion of the intermediate' inclined portion, in combination with a cooperating fastening element having a headed shank.

In testimony whereof I affix my signature.

JOHN W. lfI'lZGdERALD.y 

